This invention relates to the field of chemistry. More particularly, this invention is a technique of drying milled silicon particles.
In other methods to produce trihalosilane, a polycrystalline silicon chunk is cleaned following an acid etch. The polycrystalline silicon chunk is housed in a polyethylene basket and moved from an acid cleaning tank to a pure water rinsing tank. The cleaned silicon is then placed in a hot air dryer of about 70 degrees Celsius.
Existing methods have disadvantages such as:
(1) When the gaps between grills in the polyethylene basket are too big to hold the small silicon particle in the basket, the milled silicon particles will simply drop through.
(2) When being dried by the hot air dryer, the heat promotes the growth of resistance surface oxide.
Therefore, there is a need for an improved method of drying silicon particles.